1. If you can back your data up somewhere, I'd highly suggest doing so before anything else, just in case.
2. As already mentioned, GIVE MORE INFO - The more info you give, the more likely you are to get help.
3. If you're having error messages about unrelated items, it could very well be the motherboard and/or power supply. So...
a. Do you smell any funny smells coming from your PC now that you didn't notice before?
b. If you open the case, and look at the motherboard, do you see any
bulging/leaking capacitors?
If your desktop is the one I found
here, then I'd also look at the case cooling.. make sure the temps aren't so high that it's cooking components... it's more common to have cooling issues in smaller cases, b/c you've got less space to put stuff and not restrict air flow.
--
"If to err is human, then I must be some kind of human!" -Me